#include <bits/stdc++.h>
#define mp make_pair
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define forn(i, n) for (int i = 0; i < (int)(n); ++i)
#define for1(i, n) for (int i = 1; i <= (int)(n); ++i)
#define ford(i, a, b) for (int i = (int)(a); i >= (int)b; --i)
#define fore(i, a, b) for (int i = (int)(a); i <= (int)(b); ++i)
#define rep(i, l, r) for (int i = (l); i <= (r); i++)
#define per(i, r, l) for (int i = (r); i >= (l); i--)
#define ms(x, y) memset(x, y, sizeof(x))
#define SZ(x) int(x.size())
#define fk cerr<<"fk"<<endl
#define db(x) cerr<<(#x)<<'='<<(x)<<endl
#define db2(x,y) cerr<<(#x)<<'='<<(x)<<' '<<(#y)<<'='<<(y)<<endl
using namespace std;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pii> vpi;
typedef vector<vi> vvi;
typedef long long i64;
typedef vector<i64> vi64;
typedef vector<vi64> vvi64;
typedef pair<i64, i64> pi64;
typedef double ld;
template<class T> bool uin(T &a, T b) { return a > b ? (a = b, true) : false; }
template<class T> bool uax(T &a, T b) { return a < b ? (a = b, true) : false; }
//1.integer overflow (1e5 * 1e5) (2e9 + 2e9)
//2.runtime error
//3.boundary condition
void solve()
{
    int n,k;
    cin>>n>>k;
    vector<pii> v(n);
    rep(i,0,n-1)
    {
    	cin>>v[i].fi;
    	v[i].se=i+1;
    }
    if(k==1)
    {
        cout<<0;
        return;
    }
    if(k==n)
    {
        cout<<k-1;
        return;
    }
    sort(all(v));
    set<int> st;
    int ans=1e9;
    rep(i,0,k-1)
    {
        st.insert(v[i].se);
    }
    ans=min(ans,*st.rbegin()-*st.begin());
    rep(i,k,n-1)
    {
        auto it=st.find(v[i-k].se);
        st.erase(it);
        st.insert(v[i].se);
        ans=min(ans,*st.rbegin()-*st.begin());
    }
    cout<<ans;

}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.precision(10);
    cout<<fixed;
    int t=1;
    //cin>>t;
    while(t--)
    {
        solve();
    }
#ifdef LOCAL_DEFINE
    freopen("input.txt", "r", stdin);
#endif
    
#ifdef LOCAL_DEFINE
    cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
#endif
    return 0;
}
